In recent years, television receivers (hereinafter referred to as TVs) capable of downloading content items using communication called “Internet television” or “smart TV” and playing back the content items are becoming mainstream (for example, see Patent Literatures (hereinafter referred to as PTLs) 1 and 2)
For example, such a TV is included in a broadcast receiving apparatus that receives a broadcast content item and is connected to the Internet. The TV searches for a video that is a desired communication content via the connected Internet, and downloads and plays back the video. Furthermore, an on-demand TV receives a content item streaming-distributed from a video/music distribution site, and plays back the content. The TV downloads and executes an application program, such as a game and a utility, and has a communication function, such as a social network service.
Furthermore, a content item of a digital broadcast received by a digital broadcast receiver in a household or a digital content item stored in a recorder is transmitted to a room different from the room in which the digital broadcast receiver or the recorder is placed, using a home network, and the content is viewed in the different room.
There is an increasing tendency to enable sharing of a digital content item between all the devices connected to a home network, using the home network. Specifically, there is an increasing tendency to enable the sharing not only between all the devices such as consumer electronics (CE) devices including a television receiver and a digital video recorder (DVR), but also between all the devices that include a personal computer (PC) and a mobile information terminal called a personal digital assistant (PDA) and are connected to the home network. More specifically, the standard organizations such as the Digital Living Network Alliance (DLNA) define and release the standards and guidelines for implementing such sharing.
Here, the standard defined in the Universal Plug and Play (UPnP) AV Architecture is used for identifying devices and exchanging information on available content items, between a server on a home network (for example, a set-top box (STB) or a DVR that receives a digital broadcast) and a client (for example, a personal computer or a digital player). According to the UPnP AV, in response to an inquiry from the client, the server returns a list of provided content items and attribute information of each of the content items. Furthermore, the DLNA uses the Hypertext Transfer Protocol (HTTP) as a required protocol for communicating content data.